Imagine a world in which Ted Thompson turns radical and signs four free agents in the offseason.

No need to imagine. Thompson did it last spring when he brought in Martellus Bennett, Lance Kendricks, Jahri Evans and Davon House. He then picked up Ahmad Brooks during training camp.

Now imagine a world in which Thompson makes a big in-season trade to improve his Green Bay Packers’ chances for winning the Super Bowl.

That one really takes imagination, because it’s the kind of short-term move that Thompson steadfastly has avoided in his previous 12 years as general manager. But it’s something he needs to look at long and hard, because his Packers are bona fide championship contenders who nevertheless could use a pass rusher or cornerback to help their quest for a 14th NFL title.

We’ll start by saying that in theory this all sounds great, but the truth is that aside from quarterback the two most difficult positions to acquire a quality player are outside rusher and cornerback. Teams just aren’t unloading guys at those premium positions.

So good luck, Ted.

Yet, I can’t help but think that Ron Wolf, a Pro Football Hall of Famer, would find a way to acquire a pass rusher or cornerback by the NFL’s Oct. 31 trade deadline if he still were Packers GM.

Because these Packers have a real chance to get to and win the title. They’re 4-1 despite a spate of costly short-term injuries, especially on the offensive line. They have a premier quarterback playing at the top of his game. And it looks like they just found a running back (Aaron Jones) who can help protect Aaron Rodgers by forcing defenses to honor the run.

But the Packers also rank No. 18 in defensive passer rating and No. 20 in points allowed. They’re fine going against the Andy Daltons and Mike Glennons of the world, but as we saw in Week 2 at Atlanta, it’s a different story with the Matt Ryans. And to win the Super Bowl, you’re going to have to beat a Matt Ryan or two.

The best chance of doing that is with sacks and pressure. And the Packers (tied for No. 19 in sacks) need more of both.

Maybe Vince Biegel (fourth-round pick) and Montravius Adams (third-rounder) will provide coordinator Dom Capers a little more rush by December and January. But Biegel (PUP, broken foot) hasn’t played football since last season at Wisconsin, and Adams has been a healthy scratch the last two games. So that’s not something to count on.

So will Thompson make a move?

History says a resounding no. But considering his new approach to free agency last spring, you never know.

“I’d turn every stone upside down to see if I could get what I needed,” the aforementioned executive said when asked what he’d do if he were Thompson.

As for a pass rusher who might be had, that’s where the hard work begins. I asked a scout with another team if there were any who might be available, and as an exercise he took a few minutes to look through rosters and salary-cap hits. He found no obvious candidates.

The player I picked in a cursory look around the league was Jamie Collins Sr., a linebacker for the Cleveland Browns who was a jack-of-all-trades defender for New England. Collins, 27, had 9½ sacks in 27 games for the Patriots in 2014 and ’15. And winless Cleveland might be open to a deal because the Browns are in the mode of acquiring young (draft picks) for old.

But the scout nixed that. Collins isn’t a rusher. His value would be as an inside linebacker in the Packers’ 3-4 scheme.

That doesn’t mean there aren’t other possibilities. The closer we get to the Oct. 31 trade deadline, the more teams might be willing to deal as their playoff chances diminish. Or maybe there’s a young, unproven guy out there worth giving a shot.

As for trade ammo, Thompson has some. Not on the roster, but in the draft.

Lance Zierlein of NFL Network projects the Packers will receive four compensatory picks because of their net losses in free agency: a third, a fifth and two sevenths.

That’s a big haul.

You might remember that back in 2010 Thompson tried to deal for running back Marshawn Lynch but backed out after the bidding went from a fourth-rounder to a third. Seattle got him at that price, and it turned into a franchise-changing move.

Those compensatory picks make it a lot easier for Thompson to pull the trigger on that kind of deal, especially now that compensatory picks are in trade play as well.

Thompson is right when he says this isn’t fantasy football. It also takes two to do a deal. So nobody’s saying this is easy.

But the GM owes it to his team to change his M.O. and look far and wide. There’s a Super Bowl out there for the taking, and he has the draft picks to make a move.